1. Field of the Invention
The present invention relates to SAW based tyre pressure sensors, and in particular to adaptors which enable such sensors to be retrofitted to existing tyre inflation valves.
2. Description of the Related Prior Art
Surface Acoustic Wave devices are known in the art to be useful as pressure sensors, and they have particularly application as remote or wireless pressure and temperature sensors in tyres. These SAW based pressure sensors must be placed in fluid communication with the pressurised atmosphere within the tyre, and this is typically done either by attaching the sensor to the inner wall of the tyre or integrating it into a tyre pressure valve. Applicant's own earlier Granted UK patent GB2352814 and UK patent application no. GB021163.0 disclose a particular example of a tyre inflation valve with an integrated SAW pressure sensor. However, this system requires the fitting of a new inflation valve when installing the system into an existing wheel, and also results in the SAW sensor being disposed of every time the valve is replaced, for example when a new tire is fitted onto a rim, thereby increasing costs.